As a scale of a fiber network increases, a passive optical network (PON) technology gradually becomes a hotspot of optical access network technologies. A PON includes an optical line terminal (OLT), an optical distribution network (ODN), and an optical network unit (ONU). An important passive component in the optical distribution network is an optical splitter. The optical splitter can split and combine optical signals, and is used for allocation of an optical signal, connection of an optical path, control of a transmission direction of an optical signal, control of coupling between optical components, and the like. Because the optical splitter works in a high-temperature high-humidity environment for a long time, performance gradually deteriorates over time, which leads to an increase in a link loss until a link fails due to a large loss.
In order to ensure normal running of a PON, the PON usually needs to be detected before a service is activated, where the detection includes detection on a status of the optical splitter and detection on a loss situation of a fiber link. In the prior art, a detector usually needs to carry a testing device to a site at which an optical splitter is disposed, to perform detection. Therefore, detecting efficiency is low.